Electron microscopic localization of alpha toxin within the staphylococcal cell by ferritin-labeled antibody.

Highly purified staphylococcal alpha toxin has been used to produce monospecific anti-alpha antibody in rabbits. Gamma globulin prepared from the serum of these rabbits was coupled with ferritin by using toluene diisocyanate. Staphylococcal cells which had been disrupted by two passages through an LKB X-press were treated with this conjugate. Electron microscopic examination of this material showed alpha toxin or an antigenically mature precursor located on the cytoplasmic membrane. The possible function of alpha toxin in this situation is discussed.